As a conventional push button switch, for example, there has been a refrigerator-freezer door switch including: a case; a fixed contact terminal provided in a vicinity of a center of the case; first and second switches having first and second movable contact plates that, come into and out of contact with the fixed contact terminal; a third switch provided between the first and second switches and made up of a third movable contact plate that comes into and out of the fixed contact terminal via a pressing spring; and first and second actuating levers obtained by integrally forming, on both ends of the case, (i) actuating pieces that are projectable and sinkable and turn on pieces disposed at positions which come into and output contact with the pressing spring of the third switch so as to cross the first and second switches. The first and second switches are turned on when the first and second actuating levers project. The first and second switches are turned off when the first and second actuating levers sink. The third switch is turned on only when both the first and second actuating levers sink (cf. PTL 1).